Mechanical stair elevator



Dec. 17, 1957 E- SUNDBERG 2,816,642

MECHANICAL STAIR ELEVATOR Filed Jah. 19. 1954 ATTORNEY MECHANICAL STAIR ELEVATOR Ernst Sundlierg, Bromma, Sweden Application January 19, 1954, Serial No. 405,021

Claims priority, application Sweden May 12, 1953 Claims. (Cl. 198-16) The present invention relates to a mechanical stair elevator with steps that can be raised and lowered. In accordance with the invention every second step is rigid, while the remaining steps can be raised and lowered to the level of the adjacent rigid steps. lust as with all stair elevators of this kind it is only necessary for the person using the stair to move himself in the horizontal direction, while the motion upwards in the vertical direction is accomplished through the elevating effects of the moving steps. With a stair according to the present invention the person will alternately step on a movable and a rigid step, which will cause a more comfortable and safer passage on the stair, inasmuch as, on account of the rigid steps, a pause in the movement is achieved between two elevating movements. Besides the movement .7 mechanism becomes simpler and less expensive, when only half the number of steps are required to be set in motion.

The invention is illustrated on the accompanying drawing, which in Fig. l shows a stair elevator, according to the invention, in a side view and Fig. 2 shows a rear view Y of the same. All the steps 1, 3 are built in between two side walls 2, where the steps 1 are rigidly connected., while the steps 3 are movable in vertical guides located on the side walls 2. The movable steps are suitably designed in the shape of parallelopipedical boxes, which fully occupy the space between the rigid steps. They are arranged to execute an up and down motion between two extreme positions, in which their upper surface is on the same level as the upper surface of the rear and forward rigid step respectively.

The vertical motion of the steps is effected by a system of angular levers, supported by stationary bearings. In the shown example, every movable step is equipped with such an angular lever. This consists of an axle 6, parallel to the steps, and rotatably mounted in bearings on the side walls 2, and two, on this axle rigidly mounted, levers 5, 8. The step 3 is carried by two lifting arms 8, in the free ends of which is located a bar or an axle 9, that can turn and slide, and which is supported by bearings in the side walls of the step. Eventually the lifting arms 3 could be joined to the axle 9 with links. The levers 5 are located on the projecting ends of the axles 6, and at their free ends are rotatably connected with a pulling bar 7, which in turn is rotatably connected to an eccentric rod 10, which through a pin 11 is connected to an eccentric disk 12, driven by an electric motor 13, through some gear reduction medium.

The outside levers 5 are suitably enclosed in a housing, built onto the adjacent side wall 2. The stair elevator shouid also be equipped with hand rails along the side walls 2. The starting of the motor can be accomplished by switch, photo-electric cell or push button controls, located at first and last steps. The stair can also be designed as a spiral stair or in some other manner suitable to the existing space conditions.

In place of drive arrangement with levers, vertical and rectilinear guides drive media, could be utilized. As

nited States Patent v 2,816,642 Patented Dec. 17, 1957 an example all the movable steps could be mounted in mutually fixed positions, in a common frame, which could be arranged to perform a parallel motion, in a vertical direction. For this a hydraulic cylinder drive arrangement with the pistons connected to the frame work of the movable steps could be used to advantage.

The described stair elevator could be modified in such manner that the movable steps, located in front and in back of every rigid step, could be made to move in opposite directions, whereby the front step would be raised, at the same time as the rear step would be lowered to the level of the rigid step, lying between. Then the movement in the horizontal direction could be executed from the front movable step across the between lying rigid step, to the next following movable step, whereby the movement up the stair could be speeded up. With such arrangement the front and rear movable steps, lying adjacent to every rigid step, could be arranged to be operated by the same levers 5 and turning axles 6, when the two movable steps are supported by lifting arms, which are rigidly connected to the common axle 6. The number of levers 5 and axles 6 required is hereby reduced to one-half of the number required for the arrangement described above.

The movable steps do not necessarily have to be raised and lowered respectively to the exact level of the adjacent rigid step, but could in their upper position rest a bit lower than, and in their lower position a bit above the rigid step, thereby emphasizing the boundary between the steps, and thereby facilitating the placing of the foot in the right place on the following step. The arrangement of such relatively small difference in elevation, of say only a few centimeters, has also that advantage that the passage on this stair elevator, becomes to some extent similar to the passage on an ordinary stair way.

To lessen the power consumption, counter weights could be arranged to counter-balance either the separate steps or all the movable steps together.

Longer stairs may be arranged in two or more sections, following each other in the length direction of the stair way, where every section is composed of a stair with partly rigid steps and partly movable steps, arranged to work in a manner as described above. The various sections could then be driven independent of each other by different motors, or from the same motor. In this case the following section should preferably be started after the preceding section has been started.

What is claimed is:

1. A mechanical stair elevator having a set of movable steps, a set of stationary steps alternately interposed between the movable steps, and means for imparting a vertical reciprocating movement to the movable steps comprising lifting arms carrying the steps and swingable on K shafts located below the adjacent upper stationary steps and extending in the longitudinal direction of the steps, said shafts being interconnected by means of a bar extending longitudinally of the stair and arranged to be reciprocated.

2. A mechanical stair elevator comprising a flight of steps dened by a set of movable steps, and a set of stationary steps alternately interposed between the movable steps, means interconnecting the movable steps in mutually fixed relative positions, and means for imparting a reciprocating movement to said movable steps to move said steps between vertically-spaced-apart planes, whereby said movable steps are selectively raised simultaneously and lowered simultaneously.

3. A mechanical stair elevator comprising a flight of steps defined by a set of movable steps, and a set of stationary steps alternately interposed between the movable steps, means interconnecting the movable steps in mutually fixed relative positions, and means for imparting a reciprocating movement to said movable steps to move said steps between vertically-spaced-apart planes, whereby said movable steps are selectively raised simultaneously and lowered simultaneously', said movable steps having substantially the same surface area as said stationary steps for receiving the feet of the user of the elevator.

4. A mechanical stair elevator comprising a ight of steps dened by a set of movable steps and a set of stationary steps alternately interposed between the movable steps, frame means interconnecting the movable steps in mutually fixed relative positions, and means for imparting a reciprocating movement to said frame means to move said steps between vertically-spaced-apart planes, whereby said movable steps are selectively raised simultaneously and lowered simultaneously.

5. A mechanical stair elevator comprising a flight ol' steps defined by a set of movable steps, and a set of stationary steps alternately interposed between the movable References Cited in the lc of this patent UNITED STATES PATENTS 2,341,463 Maytham Feb. 8, 1944 2,664,990 Georgiev et al lan. 5, 1954 FOREIGN PATENTS 13,210 Great Britain May 3l, 1910 

